Revival of rabi oscillations in optically excited semiconductor quantum dots

Abstract

We present the theoretical investigation of the dynamics of strongly confined laser driven semiconductor quantum dots coupled to phonons. We provide a formally exact solution of this non-Markovian quantum decoherence problem. The method is based on the discrete time-dependent path-integral Monte Carlo technique. This method allows us to explore the cases of long pulses, arbitrary dot-phonon and dot-laser coupling and high temperatures, which up to now have been inaccessible. We find that although Rabi oscillations of the density matrix are suppressed due to phonon induced dephasing, the dephasing rate is a non-monotonic function of the laser field and that it becomes smaller at larger fields leading to a remarkable revival of the Rabi oscillations. This revival is of a general nature which for the type of systems studied here occurs for all temperatures and carrier-phonon coupling strengths.